Although oil energy has led the development of human society, it suffers from problems including finiteness of resources, regional disparities, environmental pollution, etc., and thus thorough research into fully/partially replacing oil resources with biomass is ongoing.
The term “biomass” broadly refers to any material of biological origin, and narrowly refers to a material mainly derived from plant sources such as corn, soybeans, linseed, sugar cane and palm oil, and may extend to all living organisms, or by-products of metabolism which is part of a carbon cycle.
Research into production of high-value-added materials from biomass has been extensively and intensively carried out since the 1970s, but commercially applicable independent models have not yet been presented. This is considered to be due to some defects of biomass: First, biomass resources are limited. Although too much emphasis is given to oil resources, they are currently present in amounts able to satisfy global demand for energy and chemicals. Compared to oil resources, biomass, on which less emphasis is laid, requires additional production procedures and is thus produced at a much lower level. Second, biomass has low price competitiveness. Because biomass is basically produced on the premise of consumption, cheap surplus biomass is difficult to find as a feed for replacing the oil resources. Third, there is difficulty in ensuring that a sufficient amount of biomass is available. Whereas oil resources are produced from preexisting oil blocks in specific areas and thus have no problems of additionally yielding resources, biomass typically requires a large area under cultivation and thus it is difficult to ensure produced biomass in a large enough amount to serve as a resource to replace oil.
However, techniques for overcoming the above limitations with improvements in biomass production are being provided. In particular, CPO (Crude Palm Oil) and SBO (Soybean Oil) presented as surplus biomass are globally produced in an amount of millions of tons, and the amount able to be ensured on the open market is approximately 1 million tons or more. Furthermore, as the production amount thereof increases, price volatility becomes lower than before, and purchase on the open market becomes possible. Also, because CPO may be ensured in a large amount and its price is stable on the open market, it is receiving attention as an alternative to oil-based products. CPO is composed of 90˜95% of triglyceride, and the ratio of C16 and C18 carbon chains of triglyceride is about 45:55 (by weight). A material corresponding to 5˜10 wt % that is the remainder of CPO other than triglyceride is composed mainly of C16 and/or C18 fatty acids, containing about 10% of mono- or di-glyceride. Triglyceride, which is selectively separated through refinement of CPO, is referred to as RBD (Refined Bleached Deodorized) palm oil. As such, about 5˜10 wt % of fatty acid and mono- or di-glyceride, which were removed, may be referred to as PFAD (Palm Fatty Acid Distillate). Currently, the amount of CPO which may be purchased on the open market is approximately 1 million tons, and the amount of PFAD is approximately 4 hundred thousand tons. In this regard, fatty acids, which constitute triglyceride and PFAD, are illustrated in FIG. 1. Also, carbon branches for CPO and PFAD are shown in Table 1 below.
TABLE 1Fatty acidCPO1 (wt %)PFAD2 (wt %)14:0 Myristic0.5~5.90.9~1.516:0 Palmitic32~5943~5116:1 Palmitoleic<0.6—18:0 Stearic1.5~8.04~518:1 Oleic27~5233~4018:2 Linoleic5.0~14  9~1118:3 Linolenic<1.50.2~0.620:0 Eicosanoic<1.0—1composed mainly of triglyceride2composed mainly of fatty acid
Meanwhile, drilling oil, which is called drilling fluid, boring mud, mud, drilling mud, etc., is transported under pressure to a drill bit through the center of a drill pipe upon drilling and then sprayed through a nozzle provided to the drill bit. As such, when the drilling oil pushes out rock cuttings and is recovered in the ground through a space between the hole wall and the drill pipe, the cuttings are discharged together. Such drilling oil functions (i) to remove rock cuttings, (ii) to cool the drill bit and the drill pipe, (iii) to lubricate the drill pipe, and (iv) to prevent collapse of the wall of a drill well due to back reaction to the borehole infrastructure pressure created in the course of drilling.
The drilling oil may be largely classified into oil-based and synthetic-based. The former indicates drilling oil containing no synthetic material, and includes diesel oil, mineral oil or other oil. Whereas, the latter indicates drilling oil prepared by reaction of a specifically refined chemical, and for example, may be oil synthesized by oligomerization of one or more olefin monomers in the presence of a metallocene catalyst (U.S. Pat. Nos. 5,198,012 and 6,054,415, and US Publication No. 2011/0251445). In this regard, a conventionally commercially available Chevron blend is prepared through a full range of linear α-olefin technology, and the drilling oil comprises a mixture of 1-hexadecene (C16) and 1-octadecene (C18), and the ratio of C16/C18 α-olefins is about 65/35.
The drilling oil has to satisfy specific properties in consideration of essential required functions. For example, density (specific gravity) is a property which enables a fluid column to exhibit a characteristic similar to lithostatic stress in ice depending on changes in the drilling depth. In the case where the pour point of the drilling oil is high, the viscosity of the drilling oil is drastically increased under low-temperature conditions (upon deep-sea drilling, oil drilling in the Polar Regions, etc.), and also excessive thickening may occur. Also, the case where the flash point of the drilling oil is low may incur stability problems. In addition, when the drilling oil has too low viscosity, it is impossible to exhibit the inherent function thereof which allows the cuttings to float and be transported to the surface. In contrast, when the viscosity is too high, pumping of the drilling oil becomes difficult. Hence, the viscosity of the drilling oil has to be adjusted appropriately. However, such properties counteract each other (e.g. when any one property increases, another property may deteriorate), and thus it is difficult to simultaneously satisfy the properties required of the drilling oil alone.
Also, as the drilling work conditions and the regulations for environmental pollution are enhanced, drilling oil is required not only to exhibit its inherent function but also to prevent the generation of problems to people and the environment. However, in conventional techniques, limitations are imposed on minimizing the environmental effects, such as biodegradability and/or toxicity. For example, oil-based drilling oil inevitably contains polycyclic aromatics, transition metals, sulfur, nitrogen, halogen, etc., as impurities present in crude oil, and thus additional equipment or processing for removing such impurities should be provided. Also, synthetic-based drilling oil, especially an oligomerization product of olefin, has the potential problem in which the catalyst (e.g. boron trifluoride, etc.) used for the reaction may be discharged as a toxic material. Particularly with the EPA (Environmental Protection Agency) in the USA, regulations for biodegradability, sediment toxicity, heavy metal and polycyclic aromatic contents have become stricter.
In this regard, methods of manufacturing fuel oil such as gasoline or diesel from biomass are conventionally known, but applicability of biomass to drilling oil is not. Biomass contains few components which cause environmental pollution, and is composed exclusively of carbon, hydrogen and oxygen and is thus regarded as favorable in terms of preventing environmental pollution. Moreover, in order to fulfill the increasing demand of crude oil, drilling works are frequently carried out in cold regions and the demand in improving low-temperature properties (especially, pour point) is also increasing. Furthermore, there is still a need to improve fundamental properties (flash point, specific gravity, viscosity, etc.) of drilling oil.